NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)

NEW YORK, NY - JUNE 02: Soundgarden performs at Citi Presents Exclusive Soundgarden Performance Celebrating 20th Anniversary of "Superunknown" at Webster Hall on June 2, 2014 in New York City. (Photo by Theo Wargo/Getty Images for Citi)